The Internet has established a dynamic, public environment for communication and interaction among its millions of users. In business, the Internet has redefined vendor-manufacturer, manufacturer-distributor, distributor-customer, and other relationships. With extension of the Internet technology into internal, secured networks of individual companies, the “intranet” or “private Internet”, as it is called, has enabled new forms of document and information sharing between individual employees and work groups using company directory and network infrastructure. On-line services, such as electronic bulletin boards and chat rooms, electronic commerce, and technical support for products, are available on the World Wide Web (“WWW” or “Web”) operating over the Internet.
The Internet has, at its core, a server-client architecture, in which individual clients (i.e., Internet-content users) interface via computer-executable applications such as browsers with servers (i.e., Internet-content providers) to obtain documents from Web sites. Browsers are software programs that enable personal computers to request, receive (e.g., download), interpret, and present Internet documents, and generally navigate the Internet. Web servers typically have standard interfaces for running external programs, the most common is the Common Gateway Interface (CGI). Web sites are collections of documents, usually consisting of a home page and related, linked documents, located on servers remote from the client. The documents can be compound documents, containing data, graphics, video, sound, and/or other types of media, as well as links to other documents. Essentially, the WWW is a web of interconnected documents, or, more precisely, document objects that are located at various sites on the Internet.
Among the types of document objects on the WWW are documents and scripts. A script is an executable program, or a set of commands stored in a file, that can be run by a Web server to produce a document that is then returned to the Web browser. Typical script actions include running library routines or other applications to get information from a file or database, or initiating a request to get information from another computer, or retrieving a document corresponding to a selected hypertext link. A script is run on the Web server when, for example, a user selects a particular hypertext link in the Web browser.
Underlying the Internet technology are advances in standardization, including personal computer hardware, software, network protocols, and infrastructural conventions (such as the “Uniform Resource Locator” or “URL”). URLs provide location addresses for all document objects on the WWW. A URL uniquely references a document object and often defines an access algorithm using Internet protocols.
“Internet protocols”, as that expression is used herein, are defined as current or future language conventions and present or future communication protocols that are generally-accepted and used for generating messages including documents for transmission over the Internet, or for transmitting such messages over the Internet, respectively. Such language conventions include, for example, at present, Hypertext Markup Language (“HTML”) and eXtensible Markup Language (“XML”). Such communication protocols include, for example, at present, Hypertext Transfer Protocol (“HTTP”), TCP/IP, FTP and GOPHER. Those skilled in the art will be familiar with these language conventions and protocols.
HTML is a language used for writing hypertext documents, containing multimedia content and links to other documents. An HTML document includes a hierarchical set of markup elements, where most elements have a start tag, followed by content, followed by an end tag. Tags are enclosed in angle brackets (“<” and “>”) and indicate how the document is structured and how to display the document, as well as destinations and labels for hypertext links. There are tags for markup elements such as titles, headers, text attributes such as bold and italic, lists, paragraph boundaries, external links to other documents, and internal links to other parts of the same document, graphic images, and many other document features. Many books are in wide circulation regarding programming using HTML.
XML is another of the language conventions included in the Internet protocols. XML is compatible with and complementary to HTML, at least in its current version. It is a standard way of describing a class of data objects as stored in computers, called XML documents, and behavior of programs that process these objects. XML documents are made up of storage units called entities, which contain either text or binary data. Text is made up of characters, some of which form the character content of the documents, and some of which form markup. Markup encodes a description of the document, such as its storage layout and logical structure. A software module called an XML processor is used to read XML documents and provide access to their content and structure. Further information regarding XML can be had with reference to Version 1.0 of the XML specification, available at <HTTP://www.w3.org/XML>, and incorporated herein by reference.
A Web server and a Web browser communicate typically using the HTTP message protocol and the underlying TCP/IP data transport protocol of the Internet. In HTTP, the Web browser establishes a connection to a Web server and sends an HTTP request message to the server. In response to the request message, the Web server checks authorization, performs any requested action such as downloading a document identified by its URL, and returns an HTTP response message containing either the HTML document resulting from the requested action or an error message. The returned document may simply be a static file stored on the Web server, or it may be generated dynamically using a script called in response to the request message.
To take advantage of the Internet, tools and resources have been developed in compliance with the Internet protocols, including company-critical applications such as e-mail. E-mail is electronic mail, by means of which documents are sent and received electronically at selected addresses. It has been estimated that a vast majority of Internet-based interaction is through the use of e-mail and other browser-based media that follow a “document send and receive” model. Perhaps due to that model, users often view the Internet as inherently “peer-to-peer”, with individuals accessing documents provided by other individuals, without intervention by a higher authority.
The Internet is dynamic and flexible in providing users with entertaining and useful ways of communicating, though it does not meet all the needs of users. While users interact increasingly through the Internet, they continue to interact “off” of the Internet in more conventional ways, such as through multi-medium (phone, fax, whiteboard), multi-temporal (real-time, overnight mail) and other informal means of communication.
It would be desirable to extend the Internet paradigm to personal and private communications and other shared and mutual activities between individuals and small groups in shared private spaces. Such interactions should preferably occur instantly, directly, and confidentially between participants' personal computers, or other network-capable devices, without exposing such interactions to server bottlenecks through which Internet traffic is typically funneled to third-party Web sites where communications can be intercepted and confidences violated.
It would also be desirable to provide a technique that allows users at various remote sites to share and edit documents on a peer-to-peer basis, while maintaining consistent copies of the documents at local sites. Such a technique should permit any of the users to issue change requests regarding the documents, which changes can then be made asynchronously to the copies at all the local sites in a coordinated fashion even if the sites are disconnected from the network when the change requests are issued. The technique should provide a high level of data consistency across all the sites so that each site presents essentially the same document for viewing and/or editing by the various, geographically dispersed users.